Heap Sort

I am trying to get 'nodes' into a minHeap, such that the node contains a character and its frequency (A:9) for example. I have the key/value pairs in a hashmap. Is there a way to create a 'node' of some sort out of the key/value, so that I can put them into an array, and pass it to my 'heapsort' method?

problem is, the heapSort method wants an array with ONLY the values ( i believe), so it can create the heap(array) of integers.
Then, I have to somehow create an arrayList that has the int values AND the letter they pair with, so that I can print them out.

So for example if I have a string 'This is only a test', my hashmap that I'm creating looks like(no difference between upper and lower):

t-3
h-1
i-2
s-3
space -4
o-1
n-1
l-1
y-1
a-1
e-1

So when I Iterate over the map values and insert those values into an array, I pass that array to my heapSort method, and that yields an array with:
1
1
1
1
1
1
1
2
3
3
4